Insulating gas-liquid two-phase fluids are used in heat transmission systems, cooling systems and transporting systems for liquid fuels used for space rockets, and the accurate control of their flow rate is required.
The gas-liquid two-phase fluid is very complicated as compared with a single-phase fluid, and the control performance thereof is materially decreased if a mechanism, such as a pump or a valve, employed for a single-phase fluid is used. Thus, if the two-phase fluid can be efficiently separated into a gas phase and a liquid phase, efficient use of conventional mechanisms for the single-phase fluids is made possible. No practical gas-liquid separating device has yet been developed.
In the circumstances, mechanisms such as pumps, pipe lines, valves, and the like, for single-phase fluids are used for gas-liquid two-phase fluids, after the characteristics thereof have been examined, and the lowering of performance is ignored.
Moreover, in lengthy pipe lines for liquid nitrogen and liquid helium for cooling low temperature devices, bubbles sometimes occur as a result of the vaporization of the liquids at a portion where much heat is absorbed, making it impossible to stably supply the liquids. In such a case, if the gas phase is separated from the liquid phase to change the nature of the two-phase fluid, it is possible to stabilize the flow. A gas- liquid separating device is thus necessary in the pipeline system.